U.S. Pat. No. 5,413,611 describes a prosthesis with a feedback apparatus. Feedback relating to the applied force in a driven prosthesis is generated by a vibration generator.
US 2004/0178989 A1 describes a system and a method for providing haptic feedback, in which a motor with an eccentrically arranged mass is put into motion in order to generate a vibration pattern. A similar apparatus is described in WO 03/091984 A1.